The U.S. is facing a potential railway shutdown on Jan. 1, 2016 — a shutdown that American Chemistry Council says would be more detrimental to the economy than the government shutdown of 2013.

The government shutdown in 2013 from Oct. 1 to Oct. 16 cost the US economy $24 billion. The American Chemistry Council estimates the railroad shutdown could cost the US economy $30 billion and 700,000 jobs.

To be fair, those figures are based on a monthlong railroad shutdown. The government shutdown of 2013 lasted only 16 days.

The reason for the potential shutdown is a collision avoidance system called positive train control. In 2008, Congress ordered all the railroad companies to install the system by the end of 2015.

But executives from major railway companies — like BNSF, Union Pacific and CSX — say the 2015 deadline isn't feasible, and the chairman of the Senate Commerce Committee is urging Congress to extend it.

Lawmakers have drafted a bill to extend the deadline until 2018, but if that bill doesn't pass, railways around the country could see gradual shutdowns in the coming months, just in time for the holiday season.